“The Article 50 process is now under way, and in accordance with the wishes of the British people, the United Kingdom is leaving the European Union,” British Prime Minister Theresa May said Wednesday, informing the House of Commons that she has begun the formal process of unraveling the U.K.’s membership in the European bloc.

May spoke after signing a letter to the EU that affirms the Brexit that voters embraced last June. She said that letter has now been delivered to the president of the European Council.

The prime minister said:

“This is an historic moment, from which there can be no turning back. Britain is leaving the European Union. We are going to make our own decisions and our own laws. We are going to take control of the things that matter most to us. And we are going to take this opportunity to build a stronger, fairer Britain — a country that our children and grandchildren are proud to call home. That is our ambition and our opportunity, and that is what this government is determined to do.”

We’ve updated this post with news from Britain and May’s speech.

Ahead of that speech, she told ministers of Parliament, “On today of all days, we should be coming together as a United Kingdom.”

The prime minister’s letter will trigger Article 50, the exit clause in the EU constitution. Leaving the EU won’t be a simple affair: While business and travel concerns often get the most attention, Britain’s government will also have to figure out how it will incorporate the thousands of laws and rules that the EU has approved over the years.

With Britain looking to exit from the EU, the nation may also be forced to contemplate an internal exit of its own: One day before May visited Parliament, Scottish lawmakers voted to back First Minister Nicola Sturgeon’s pursuit of a new independence referendum.

In 2014, 55 percent of Scottish voters chose to stay in the U.K. — but backers of a new referendum note that conditions have now changed, with the pending exit from the EU.

With Article 50 invoked, Britain will have two years to negotiate its self-extraction. Next steps in the process will begin Thursday with the publishing of a Great Repeal Bill. Formal talks could begin by late spring, but before a deal is enacted, both houses of Parliament will need to vote on it.

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